The tendency of girls to take pictures with everyone at a party (regardless of whether or not they like the people in the photos), so that if something awkward or embarrassing happens with someone during the course of that party, there is usually a photo of them before that incident happened.

"Look at that picture of Michael, Ella, and Isabel"
"Weren't Ella and Isabel in a catfight that night?"
"Yeah but this was at the beginning of the night, it's clearly a retroactively-awkward photo op."